nRF Connect iOS App: Is Disconnect Immediate?

[FluffyMarshMallow26]

Hello - we're using "nRF Connect" from the Apple App Store for the development of our project.

First, thank you for making this tool available and free for everyone to use.

Second, I've a question regarding disconnecting.  I can connect easily to my BLE peripheral and see the results in the app; however, when I connect and then immediately disconnect, I notice from my peripheral log that it does not register a disconnect until (typically) 12 seconds later, give or take 2 seconds.  In some cases it takes 6.3 seconds but usually not.  On the other hand, if I connect using the nRF Connect app but then immediately disabled "Bluetooth" in my Apple phone's settings menu, the peripherals logs the disconnect immediately.

My question:  Is this a function of the nRF Connect application maintaining a connected status for a fixed window interval or could this be something else (a Bluetooth signalling standard, sunspots, owl infestation, my terrible code, etc.)?

Thanks for any response!

[Einar Thorsrud]

Hi,

I just tested nRF Connect 2.4.7 on iOS 14.4 on an iPhone 11 and disconnects seems to be more or less instantaneous. I have not been able to reproduce the behaviour you describe. Could it be something about how you handle the disconnect on the nRF so that perhaps the log message indicating disconnect or similar is delayed? Perhaps you could verify with a BLE sniffer if the iPhone sends the disconnect message immediately or not?

[FluffyMarshMallow26]

Thank you - we are going to chalk this one up to the library we are using (ArduinoBLE) and assume that it is overhead associated with the connection process not allowing a rapid break.  In any case, it is not that important, but we were curious nonetheless.  We appreciate you taking time to respond!